Form 1:
The cell

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Tissues

A tissue is a group of cells of a particular type that are grouped together to perform the same function.

a) Tissue types in animals

examples are:

1. Epithelial tissue- This is a thin continuous layer of cells for lining and protection of internal and external surfaces.

2. Skeletal muscle- This is a bundle or sheets of elongated cells with fibres that can contract. Its contraction and relaxation brings about movement.

3. Blood tissue- This is a fluid containing red blood cells, white blood cells and platelets. The main functions of blood tissue are transportation of nutrients and gases as well as protection of the body against infections.

4. Connective tissue- This tissue consists of strong fibres that connects other tissues and organs thereby holding them in position.

5.Nerve Tissue-Consist of cells which are interconnected axons to enable trasmission.Receive stimuli and transmit impulses and co-ordinate body activities.

b) Tissue types in plants

examples are:

1. Epidermal tissue- This is a single thin layer of cells covering the outer surfaces. It protects inner tissues of plants from mechanical damage and infection.

2. Palisade tissue- This is a group of cells rich in chloroplasts containing chlorophyll. It has a site for the absorption of light energy and manufacture of food by photosynthesis.

3. Parenchyma tissue- This tissue consists of special thin walled irregularly shaped cells. They form packaging and storage cells.

4. Conducting tissue/Vascular bundle- This tissue consists of xylem and phloem. Xylem conducts water and dissolved mineral salts in a plant while phloem conducts food substances in solution.